Many high-speed highways and other major roadways have reinforced concrete safety barriers positioned along their boundaries. These barriers are typically steel reinforced concrete barriers of about 40" in height, which are adapted to be joined one to the other in end-to-end relation so as to form a continuous barrier means with each safety barrier forming one section thereof. Such safety barriers are used most commonly along sections of highway or roadway where there is a high risk of vehicles crossing into an oncoming lane of traffic, or a high risk of vehicles veering off the highway and creating an unsafe situation for the passengers of the vehicle or for other parties. Barriers of this general type are commonly referred to in the trade as "Jersey" barriers, denoting the alleged first usage of this type of barrier in the state of New Jersey, U.S.A.
It has become increasingly common to erect such concrete safety barriers along the sides of bridges and overpasses so as to preclude, or at least lessen, the chance of a vehicle driving or otherwise falling over the side of the bridge or overpass, which can cause severe injury or death not only to the passengers in the vehicle, but also to other parties below the bridge or overpass. In this latter instance, the damage and danger to life from the secondary impact of the vehicle or portions of the concrete safety barrier hitting persons on the ground may be more serious than the original accident which caused the vehicle to leave the bridge or overpass.
Used in conjunction with the aforementioned safety barriers are cooperating acoustical barriers that are adapted to attenuate the sound level of roadway traffic noise as it is perceived from beyond the roadway. These acoustical barriers are typically situated on top of the cooperating safety barriers. In the event of an impact by a vehicle with the safety barriers, the cooperating acoustical barriers that are situated in conjunction therewith are also potentially subject to this impact, so that the same safety considerations apply to such acoustical barriers as to the concrete safety barriers, particularly when use in conjunction with a bridge or overpass.
One such type of acoustical barrier is disclosed in U.S. Pat. No. 4,325,457 to Docherty et al., which patent is incorporated herein by reference. This acoustical barrier system comprises a plurality of individual panels situated in stacked relation with respect to one another between a series of evenly spaced vertically disposed "H" beams, the "H" beams spaced apart at a distance just slightly greater than the width of the sound barrier panels. The acoustical barrier panels fit in interposed relation between adjacent "H" beams and are held in place by the flanges of these beams, in a specific manner as described in the patent. The acoustical barrier panels are substantially of the same width as the sections of the safety barriers atop which they sit. A single width of acoustical barrier panels stacked between two adjacent "H" beams is are hereinafter referred to as a "section".
These and similar acoustical barrier panels are typically put into place at the job site by lifting them using a crane or similar lifting apparatus, and then lowering each acoustical barrier panel into place, one on top of another. It is common to have about six to eight panels stacked one on top of another to form a section of acoustical barrier system of required height.
There are two distinct problematic areas associated with known prior art acoustical barrier panels of the general type described above. The first problem area centres around inefficiencies with the installation of prior art acoustical barrier panels. The installation of known acoustical barrier panels into place between adjacent "H" beam frame members is difficult, expensive and time consuming for several reasons. Firstly, the barrier panels, which are awkward to handle, must be put into place on top of each other one at a time. Moreover, erecting the acoustical barrier sections must be performed in an in situ setting, which is typically more dangerous, more time consuming and more costly than performing the same job in a factory type environment. Also, in situ construction is subject to postponement by reason of inclement weather conditions. Further, the rental of equipment, such as cranes and trucks to transport and handle prior art acoustical panels, may be prolonged, due to the lengthy construction time required to assemble prior art acoustical barrier panel sections. Therefore, any decrease in the amount of pre-assembly of the acoustical panel sections that can be carried out in a factory setting will result in significant savings in terms of on-site labour, transportation and relating handling charges.
The second problem area with known acoustical barrier panel systems concerns traffic accidents where vehicles impact with the safety barriers and the cooperating acoustical sound barrier panels. It is common for the acoustical barrier panels to be broken during such impact, and subsequently fall in whole or in part from the "H" beam support frame in which they were retained. Such displaced panels, or portions thereof, may fall onto either the roadway or by the shoulder of the roadway. Where the displaced panels fall onto an unused shoulder of the roadway, this is generally not a serious problem, as no harm would normally be done. However, if the acoustical barrier panels are installed, for example, on a bridge or overpass, or immediately beside a parking lot, playground, residential building, or any other area frequented by persons, serious personal injury to those not otherwise involved in a vehicle accident might occur. Accordingly, it has generally been seen as undesirable to have acoustical barrier panels of the general type described installed on bridges, overpasses etc. Further, small fragments of the composite material of the barrier panel might become separated off the barrier panels under the forceful impact of a vehicle, so as to become projectiles.
Therefore, from the safety standpoint, what is needed is an acoustical barrier panel that precludes portions thereof from being dislodged from the initial retained, assembled configuration in the event of an impact by a vehicle.
What is also needed is an improved acoustical barrier system wherein the panels comprising a section of the system do not need to be put in place in situ, one panel at a time.
It is an object of the present invention to provide an acoustical barrier panel system having a plurality of acoustical barrier panels that are adapted to be installed in place between upright frame members to form a section to the acoustical barrier panel system in a single construction operation.
It is another object of the present invention to provide an acoustical barrier panel system that is adapted for pre-assembly of acoustical barrier panels into one complete acoustical barrier panel section in a factory environment, and subsequent installation of the entire acoustical barrier panel section on-site.
It is yet another object of the present invention to provide an acoustical barrier panel system having improved safety characteristics.
It is a further object of the present invention to provide an acoustical barrier panel system having acoustical barrier panels that are adapted to be held substantially in place by the upright frame members of the system in the event that the acoustical barrier panels are damaged through impact with a vehicle or other moving object.
It is yet a further object of the present invention to provide an acoustical barrier panel system having acoustical barrier panels that are adapted to preclude any substantial fragments of panel material from becoming separated from the panels by reason of an impact with a vehicle.